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