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