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