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