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