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