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