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