One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,3,4)(9,10)(11,14)(12,13)(15,16)(17,18)(19,23)(20,24)(21,26)(22,25)(27,31)(28,30)(29,32)(5,6)(7,8)(10,13)(14,16)(17,19,22,28)(18,23,25,30)(20,29,27,21)(24,32,31,26)(2,4)(6,8)(9,11)(10,14)(12,15)(13,16)(17,20,21,19,22,27,29,28)(18,24,26,23,25,31,32,30)(11,15)(14,16)(18,25)(23,30)(24,31)(26,32) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.