There is no "diagram" showing the whole routing of fuel lines in the bike. You need to use different diagrams in Fuel System section of the service manual. Fuel system section starts at page 15 in service manual, but what you really need starts at page 40. I have posted fuel service manual at the end of comment.
There is one forum where users discussed the routing. One user has colored the diagram from service manual to indicate lines routing. Here the diagram:
Here the forum,
"The red and yellow are the fuel lines that go to the petcock. The green
one you left unmarked also goes to the petcock. The line with a question
mark is a vacuum line that connects to a part in front of the battery
along with the larger lines to the cylinders."Here the service manual in PDF format.