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