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