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