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