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