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