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