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