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