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