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