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