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