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