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