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