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