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