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