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