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