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