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