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