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