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