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