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