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