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