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