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