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