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