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