Logo is actually more than just a toy language for turtle graphics. It's a serious language with a lot of inspiration from Lisp (although not using sexps).
I seem to recall at least one Logo I used as a kid had an "advanced mode" that in hindsight boiled down to S-Expressions and several more Lisp functions added to its standard library. Wish I could recall which Logo that was. Maybe one of the later LCSI builds (Apple Logo or IBM Logo), but possibly some version of Lego's TC Logo?
About S-expressions, you can fully parenthesize everything if you want. But Logo uses square brackets, not parens, as list delimiters, so you still have to do a little bit of tokenization.
Doesn't look like IBM Logo, from a glance at the manual on my shelf. IBM Logo did have a `startup` feature, which Rebol and Red (pending security design issues) use, so you can pre-load things into your environment.