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