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