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