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