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