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