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