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