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