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)(11,17)(12,20)(13,18)(14,15)(16,22)(19,21)(23,24)(26,29)(28,36)(31,33)(34,40) involution — undirected(2,6)(3,8)(10,15)(13,17)(16,20)(21,23)(26,29)(31,33)(32,37)(38,39) involution — undirected(1,3)(2,4)(5,8)(6,7)(10,15)(11,18)(16,20)(19,24)(25,26,30,29)(27,33,35,31)(28,32,36,37)(34,39,40,38)(1,4)(2,3)(5,7)(6,8)(9,11)(10,13)(12,19)(14,18)(15,17)(16,21)(20,23)(22,24)(25,27,30,35)(26,31,29,33)(28,34,36,40)(32,38,37,39)(1,2)(3,4)(5,6)(7,8)(9,12,14,22)(10,16,15,20)(11,19,18,24)(13,21,17,23)(25,28)(26,32)(27,34)(29,37)(30,36)(31,38)(33,39)(35,40)(1,4)(2,3)(5,7)(6,8)(9,13)(10,11)(12,21)(14,17)(15,18)(16,19)(20,24)(22,23)(25,29,30,26)(27,33,35,31)(28,37,36,32)(34,39,40,38)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.