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