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