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