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)(25,26,30,31)(27,29,33,37)(28,32,35,38)(34,36,39,40)(1,2)(3,7)(4,6)(5,8)(10,14)(11,17)(16,20)(19,21)(28,35)(32,38)(34,39)(36,40) involution — undirected(1,3)(2,5)(4,8)(6,7)(10,14)(15,18)(16,20)(23,24)(26,31)(27,33)(32,38)(34,39) involution — undirected(2,6)(5,7)(9,10)(11,18)(12,16)(13,14)(15,17)(19,24)(20,22)(21,23)(25,27)(26,29)(28,34)(30,33)(31,37)(32,36)(35,39)(38,40) involution — undirected(1,2)(3,5)(4,6)(7,8)(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)(4,8)(5,6)(9,12)(10,16)(11,19)(13,22)(14,20)(15,23)(17,21)(18,24)(25,29)(26,27)(28,36)(30,37)(31,33)(32,34)(35,40)(38,39) 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.