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