You base the graph not on 168 or 56 hours, but a 'goal' weekly time OR the highest weekly time total of the entire training program. You want to see if you fell short, met, or exceeded your weekly goal. Comparing it to how many TOTAL hours in a week or day doesn't mean anything. No one but pros train 30-40, and probably not very often. For example, look at a typical IM training program: they peak at 17-20 hours per week, three weeks out, with most of the other weeks falling somewhere between 10-15. So depending on the training program you are using (sprint, olympic, etc.), if it calls for a 20-hour MAX week, you might set your denominator for the entire spectrum of the graph at 20 hours. But it would be more accurate in the long term to look at each week's time goal (ie, 11 hours) and divide into that what you actually achieved (ie, 10 hour, or 91%)

Don't worry about comparing your workout hours to the hours in a week....all you need to do is compare one week to the next to the next.

So if you train 15 hours, then 16, then 17.5 then 11 your graph would look something like this:

Of course you can use different graph formats, but the point is that it doesn't matter how many hours there are in a day or a week. You get all of your workout data for the week, and that is really all you are looking for.

Edit: Fast posted by ChunkyB!

Every training plan will have a maximum weekly workout volume (prior to taper), including maximum volumes for S/B/R. If I were plotting it, I'd simply use a bar or scatter plot where the max values are the greatest hourly volumes that your plan calls for in any given week. In other words, say you put in a total of 12 hours training last week. If your longest week calls for 16 hours, then you just did 75% of your peak weekly volume. I would do the same for S/B/R volumes so that you can see yourself progressing toward the limit of your training. Seeing progress is good for morale, and it will also help you gauge your current fitness against your planned fitness.

If you were to take Sprint/International, Half Ironman and Ironman, what would you say would be the biggest week for each given the person is an age grouper. I know someone mentioned above that 20 hours is the biggest week for IM but I know I'll go over that so I was thinking 30 hours.

To break it evenly, would 10 for sprint, 20 for International and 30 for IM sound right or am I way off?

Edit: combined sprint/int, added HIM

Ok, so I've changed it to a meter and based on your feedback, I've changed the max number to 20 hours. If you go over 20 hours which isn't going to be that often anyway, it'll just peg the end. So as you can see, I'm at 15 hours this week so I wind up in the Ironman range. I know, it's silly but i have to entertain myself somehow. ;) Here's a pic...

http://i25.tinypic.com/2vbnbyc.jpg