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