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