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