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