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