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