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