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