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