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