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