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