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