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