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