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