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