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