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