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