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