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