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