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