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