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