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