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)(17,18,24,27,22,21,23,26)(19,28,30,32,29,20,25,31)(2,5)(6,8)(9,11,12,15)(10,13,14,16)(17,19)(18,20)(21,28)(22,29)(23,25)(24,30)(26,32)(27,31)(1,3)(2,6)(4,7)(5,8)(10,14)(13,16)(17,20)(18,25)(19,27)(21,30)(22,28)(23,32)(24,31)(26,29) involution — undirected(3,7)(6,8)(17,21,24,26,22,18,23,27)(19,28,30,32,29,20,25,31)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.