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