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