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