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