I'm pretty sure there's a Linux version of Graphviz, and you don't need SNFindPath to use it.
Excel does (and thus OpenOffice or LiberOffice should) connect to MDBs and pull info out of them.
Just pull all the information from the warp points table in the MDB and use Excel to format and concatenate the info into something you can paste into GraphViz.
If you need an example of the GraphViz code, I can provide, but it's pretty simple.
EDIT: Meh, here's the code.
Once you get your data table imported from the MDB, make a cell in each row with this code
=C2&" -> "&LEFT(D2,LE