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