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