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