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