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