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