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