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