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