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