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