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