If you create a large number of graphs, NodeXL's graph summary feature might be useful to you.
NodeXL automatically keeps track of several aspects of how a graph was created—how it was laid out, how its visual properties were set using Autofill Columns, how its vertices were grouped, and so on. It will provide you with a summary of this information, which you can use for your own documentation.
Note that for privacy reasons, NodeXL does not keep track of the most recent data that was imported into the workbook unless you tell it to.