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