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