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