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