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