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