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