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