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