So, there happens to be this thing called "TennoTyper." It is indeed a website that lets you type in English, and have it pop out an image in the Warframe alphabet of your choice (Grineer, Corpus, and Orokin). Grineer is mostly a straight cipher, as is Corpus (though technically their letters would be jumbled up, if you look at the Wiki page for the Corpus language it explains what I mean), but obviously the coolest thing is the Tenno cipher.
You have to type in phonetics for it to be accurate (recommend turning on "manual override" so you can do this more freely, otherwise it tries to guess how the word is pronounced, often poorly), but there's a cheatsheet that explains that, and it's right there on the website too.
I realize this sounds like an infomercial but it's pretty cool, and it's definitely preferable to trying to draw out the Orokin alphabet for yourself (unless you have a calligrapher's ink pen and actual artistic talent).
This is "pizzacheetah" in the Tenno alphabet, or more specifically, it's "peetsucheetu," because of the aforementioned phonetics.