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