One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,8)(10,13)(14,15)(18,23)(19,27)(21,22)(24,28)(29,30)(31,32) involution — undirected(9,10,12,13)(11,15,16,14)(17,18)(19,28)(20,23)(21,26)(22,25)(24,30)(27,31)(29,32)(2,4)(17,19,20,29)(18,24,23,31)(21,30,22,27)(25,28,26,32)(6,8)(9,11,12,16)(10,14,13,15)(18,23)(24,31)(25,26)(28,32)A 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.