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