Amphonyx lucifer

I am pretty sure it is not Manduca rustica. I think it might be Amphonyx lucifer, formerly called Cocytius lucifer. But I am not 100% sure, you have to verify. If you look at the pictures in the links you can again see the great variability. Yours seems to be quite a fresh one with excellent markings, whereas some of the specimens are old and worn and colors partly washed out. And there is also a difference in coloring between females and males.
http://www.guianensis.fr/images/sphingid...
http://www.lepbarcoding.org/sphingidae/s...
http://www.flickr.com/photos/36494393@N0...
http://www.guianensis.fr/images/imagos/S...
And here would be Manduca rustica:
http://www.silkmoths.bizland.com/mrustru...

Sphingidae sp. commonly known as hawk moths, sphinx moths and hornworms, includes about 1,200 species. It is best represented in the tropics but there are species in every region

Look like a hawk moth

What an amazing sphinx moth!