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