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