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)(25,26,31,36)(27,32,39,48)(28,34,42,52)(29,35,30,33)(37,46,40,50)(38,45,43,47)(41,49,44,51)(53,56,54,55)(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)(26,32)(28,40)(29,43)(30,38)(31,39)(33,45)(34,50)(35,47)(36,48)(37,42)(41,53)(44,54)(46,52)(49,56)(51,55)(2,5)(6,8)(9,12,14,13)(10,16,17,22)(11,19,21,20)(15,23,18,24)(26,33)(29,30)(32,45)(34,49)(35,36)(38,43)(41,44)(46,55)(47,48)(50,56)(51,52)(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)(26,34)(27,37)(29,44)(30,41)(31,42)(32,46)(33,49)(35,51)(36,52)(38,54)(39,40)(43,53)(45,55)(47,56)(48,50)(2,5)(6,8)(11,21)(15,18)(19,20)(23,24)(25,29,31,30)(26,35,36,33)(27,38,39,43)(28,41,42,44)(32,45,48,47)(34,49,52,51)(37,53,40,54)(46,56,50,55)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.