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