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