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