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