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