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