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