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