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