What exactly diagram you are looking for?
It's hard to find a bitcoin diagram but maybe this one that you are looking for, check the image below.

http://i.imgur.com/WjJsnRN.png
Or like this one
https://thefutureofbitcoins.files.wordpress.com/2014/09/bitcoin-diagram.jpg

Sorry the forum image code couldn't work so I put the url here so that you can check if this is the diagram that you are looking for.