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