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