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