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