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