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