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