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