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