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