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