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