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