Hi Alexandra,
Good q — in general, you will want to make one main diagram (or set of diagrams, if you decide to split the game into multiple frames — I’ll be talking about this more as you get deeper into the book), and then, when necessary, create new diagrams next to individual problems. One thing to know is that many q’s won’t require new diagrams, and others will just require you to jot down some notes or recreate just a part of your diagram —
HTH — Mike