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