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