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