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