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