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