One vertex per element, one color per generator, with an edge from x to x·s.
(3,8)(5,7)(9,10)(11,21)(12,26)(13,30)(14,36)(15,19)(16,23)(17,27)(18,34)(20,33)(22,49)(24,54)(25,40)(28,60)(29,63)(31,65)(32,47)(35,64)(37,45)(38,61)(39,67)(41,51)(42,68)(43,62)(44,57)(46,55)(48,53)(50,59)(52,70)(56,69)(58,72)(66,71) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,11,14,25,15,23,33,53)(10,16,20,40,19,21,36,48)(12,22,29,52,28,50,37,58)(13,31,34,67,35,24,55,57)(17,41,42,71,43,38,47,69)(18,44,30,54,46,39,64,65)(26,59,45,70,60,49,63,72)(27,61,32,66,62,51,68,56)(2,5)(3,8)(6,7)(9,12)(10,17)(11,22,23,50)(13,32)(14,37)(15,28)(16,38,21,41)(18,45)(19,43)(20,47)(24,56,31,66)(25,58,53,52)(26,30)(27,34)(29,33)(35,68)(36,42)(39,70,44,72)(40,71,48,69)(46,63)(49,65,59,54)(51,67,61,57)(55,62)(60,64)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.