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