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