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