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