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