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