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