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