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