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