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