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