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