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