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