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