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