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