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