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