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