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