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