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