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