One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,16)(4,22)(5,28)(6,14)(7,13)(8,31)(9,15)(10,19)(11,25)(12,29)(17,34)(18,51)(20,37)(21,43)(23,56)(24,59)(26,41)(27,44)(30,42)(32,36)(33,40)(35,53)(38,58)(39,61)(45,49)(46,52)(47,54)(48,62)(50,63)(55,60)(57,64) involution — undirected(1,3)(2,10,15,37)(4,23)(5,18)(6,19)(7,20)(8,32)(9,21)(11,38,41,56)(12,35,31,51)(13,16,14,43)(17,24)(22,54,44,64)(25,47)(26,57)(27,58)(28,46,42,36)(29,52)(30,53)(33,49)(34,55,63,40)(39,45,59,62)(48,60)(50,61)(1,4,6,25,9,27,7,26)(2,11,14,44,15,41,13,22)(3,17,19,48,21,50,20,49)(5,24,29,60,30,61,8,33)(10,34,43,62,37,63,16,45)(12,39,42,40,31,59,28,55)(18,47,52,58,53,57,32,23)(35,38,36,64,51,56,46,54)(1,5,6,29,9,30,7,8)(2,12,13,28,15,31,14,42)(3,18,19,52,21,53,20,32)(4,24,25,60,27,61,26,33)(10,35,16,46,37,51,43,36)(11,39,22,55,41,59,44,40)(17,47,48,58,50,57,49,23)(34,38,45,54,63,56,62,64)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.