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