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