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