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