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