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