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