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