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