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