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