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