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