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