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