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