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