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