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