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