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