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