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