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