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)(11,20)(12,17)(13,18)(14,26)(15,19)(16,22)(21,36)(23,30)(24,32)(25,33)(27,31)(28,34)(29,38)(35,39)(37,40) involution — undirected(1,3)(2,5)(4,7)(6,8)(9,11)(10,16)(12,21)(13,22)(14,27)(15,23)(17,29)(18,30)(19,31)(20,26)(24,37)(25,39)(28,38)(32,36)(33,40)(34,35) involution — undirected(3,7)(5,8)(9,12)(10,17)(11,21)(13,24)(14,28)(15,25)(16,29)(18,32)(19,33)(20,35)(22,37)(23,39)(26,34)(27,38)(30,36)(31,40) involution — undirected(2,6)(5,8)(9,13,15,14)(10,18,19,26)(11,22,23,27)(12,24,25,28)(16,30,31,20)(17,32,33,34)(21,37,39,38)(29,36,40,35)(10,19)(16,31)(17,33)(18,26)(20,30)(29,40)(32,34)(35,36) 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.