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)(11,17)(12,20)(13,19)(14,15)(16,21)(18,23)(22,24)(25,26,30,32)(27,31,35,40)(28,33,37,39)(29,34,36,38)(3,7)(5,8)(9,11,14,19)(10,13,15,17)(12,18,21,22)(16,23,20,24)(25,27,30,35)(26,31,32,40)(28,36,37,29)(33,38,39,34)(1,2)(3,5)(4,6)(7,8)(10,15)(12,21)(13,17)(18,22)(26,32)(27,35)(28,37)(34,38) involution — undirected(9,12)(10,16)(11,18)(13,23)(14,21)(15,20)(17,24)(19,22)(25,28)(26,33)(27,36)(29,35)(30,37)(31,38)(32,39)(34,40) involution — undirected(1,3)(2,5)(4,7)(6,8)(9,11)(10,17)(12,22)(13,15)(14,19)(16,23)(18,21)(20,24)(25,29,30,36)(26,34,32,38)(27,37,35,28)(31,39,40,33)(1,2)(3,5)(4,6)(7,8)(9,13,14,17)(10,11,15,19)(12,23,21,24)(16,18,20,22)(25,26)(27,31)(28,33)(29,34)(30,32)(35,40)(36,38)(37,39)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.