One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,3,4)(5,6)(7,17)(8,13)(9,14)(10,29)(11,16)(12,20)(15,33)(18,48)(19,49)(21,45)(22,57)(23,46)(24,40)(25,60)(26,42)(27,47)(28,44)(30,36)(31,39)(32,43)(34,55)(35,56)(37,51)(38,58)(41,54)(50,65)(52,62)(53,64)(59,66)(61,68)(63,67)(2,4)(5,7,11,21)(6,12,16,36)(8,18,24,52)(9,25,28,56)(10,30,33,20)(13,37,40,34)(14,41,44,49)(15,45,29,17)(19,32,54,27)(22,53,58,68)(23,55,31,51)(26,50,59,67)(35,47,60,43)(38,65,57,63)(39,62,46,48)(42,64,66,61)(1,2)(3,4)(5,8)(6,13)(7,18)(9,26)(10,31)(11,24)(12,34)(14,42)(15,46)(16,40)(17,48)(19,53)(20,55)(21,52)(22,27)(23,33)(25,50)(28,59)(29,39)(30,51)(32,58)(35,63)(36,37)(38,43)(41,61)(44,66)(45,62)(47,57)(49,64)(54,68)(56,67)(60,65) involution — undirected(2,4)(5,9,11,28)(6,14,16,44)(7,19,21,54)(8,22,24,58)(10,32,33,27)(12,35,36,60)(13,38,40,57)(15,47,29,43)(17,49,45,41)(18,50,52,67)(20,56,30,25)(23,59,31,26)(34,61,37,64)(39,66,46,42)(48,63,62,65)(51,68,55,53)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.