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