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