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