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