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