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