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