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