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