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