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