I don't have diagrams any more. I used to do that but since doing market, my own gardens have been neglected. My daughter is precise about tracking her plants. I did do a diagram for my echinacea row in the garden because the tags kept getting mixed up or lost. I even put it in my phone so when I'm in the garden I can double check it.
For my tomatoes, I always plant alphabetically and make a list in my phone for the same reason. After a couple of weeks I pretty much remember them, but you know, getting older, I have those senior moments.