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