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