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