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