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