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