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