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