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