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