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