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