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