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