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