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