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