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