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