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