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