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