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