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