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