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