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