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