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