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