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