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