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