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