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