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