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