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