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