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