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