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