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)(11,17)(12,18)(13,16)(14,15)(19,22)(20,21)(23,24)(25,26)(27,29)(28,36)(30,32)(31,38)(33,35)(34,37)(39,40)(2,5)(6,7)(10,15)(11,18)(16,24)(19,21)(25,27,30,35)(26,29,32,33)(28,34,38,40)(31,39,36,37)(1,2)(3,6)(4,5)(7,8)(10,15)(11,18)(16,24)(19,21)(25,26,30,32)(27,33,35,29)(28,31,38,36)(34,37,40,39)(1,2)(3,6)(4,5)(7,8)(9,11)(10,12)(13,21)(14,18)(15,17)(16,22)(19,23)(20,24)(25,26)(27,33)(28,31)(29,35)(30,32)(34,37)(36,38)(39,40) involution — undirected(1,3)(2,6)(4,8)(5,7)(9,12)(10,11)(13,22)(14,17)(15,18)(16,21)(19,24)(20,23)(25,28)(26,31)(27,34)(29,39)(30,38)(32,36)(33,37)(35,40) involution — undirected(9,13,14,23)(10,16,15,24)(11,19,18,21)(12,20,17,22)(25,29,30,33)(26,27,32,35)(28,37,38,39)(31,40,36,34)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.