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