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