One vertex per element, one color per generator, with an edge from x to x·s.
(2,5)(6,8)(9,10,12,16,13,17,14,18)(11,19,22,24,21,15,20,23)(25,26,28,34,30,33,29,32)(27,31,37,39,36,38,35,40)(1,2,4,5)(3,6,7,8)(9,11,13,21)(10,15,17,19)(12,22,14,20)(16,23,18,24)(25,27)(26,31)(28,37)(29,35)(30,36)(32,40)(33,38)(34,39)(1,3)(2,6)(4,7)(5,8)(10,16)(12,14)(15,23)(17,18)(19,24)(20,22)(26,32)(27,35)(28,29)(31,38)(33,34)(36,37) involution — undirected(3,7)(6,8)(9,12,13,14)(10,16,17,18)(11,20,21,22)(15,24,19,23)(26,33)(27,36)(32,34)(35,37)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.