Tim,
I like your first drawing you posted. I'm not a big fan on detailing the prints for the multi-color cabling, or the cable's between the main and sub panels. Your first print shows the wires going from the main to the sub, that’s all I need. To me this is very basic knowledge and putting all this cable routing, type of cable etc. just clutters up the print. For trouble shooting purposes, there are labels on each end of the wire and the wire is even color-coded. At some point the main and sub panels are going to be opened up and a quick visual will tell me more than anything.
I've seen prints that had multi-conductor cables running through several sub-panels. The best I've seen so far is a page, or pages of the cable routing. This was nice because if I needed that information it was designated to its own page and not all over the plc input and output pages. It still comes down to preference and if it works for you then go for it.
Tim