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