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