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