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