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