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