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