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