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