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