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