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