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