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)(11,12)(13,21)(14,15)(16,18)(17,22)(19,23)(20,24)(25,26)(27,32)(28,29)(30,38)(31,33)(34,39)(35,37)(36,40)(2,5)(3,8)(10,15)(12,16)(17,21)(20,23)(25,27,31,28)(26,32,33,29)(30,35,39,36)(34,40,38,37)(1,3)(2,6)(4,5)(7,8)(10,15)(11,18)(13,22)(20,23)(26,33)(27,28)(30,39)(37,40) involution — undirected(1,4,7,6)(2,3,5,8)(9,11,14,18)(10,16,15,12)(13,19,22,24)(17,23,21,20)(25,28,31,27)(26,29,33,32)(30,36,39,35)(34,37,38,40)(1,5,7,2)(3,4,8,6)(9,12,14,16)(10,11,15,18)(13,20,22,23)(17,19,21,24)(25,29)(26,28)(27,33)(30,37)(31,32)(34,36)(35,38)(39,40)(1,6,7,4)(2,8,5,3)(9,13,14,22)(10,17,15,21)(11,19,18,24)(12,20,16,23)(25,30)(26,34)(27,35)(28,36)(29,37)(31,39)(32,40)(33,38)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.