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