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