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