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