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