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