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