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