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