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