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