Since you mention several themes, you might want to point out that some of them are interrelated and can be discussed together. For example, the theme of social snobbery is tied in with the theme of "appearance versus reality." Social snobbery usually refers to the way society looks down on people due to the circumstances beyond their control—how much money they have, their looks, their background. In other words, social snobbery is all about appearance rather than reality. There are many incidents in Pygmalion where people are judged solely upon their appearance.
The theme of social transformation is likewise related to the theme of education and the theme of creation. Higgins sets out originally to merely "educate" Eliza. (He does have some social transformation in mind, but he thinks it will be merely superfluous and temporary.) However, due to the process of education, Eliza actually becomes someone else—she is unable to go back to her old self and old life—and Higgins, in essence, has created a new person. It is important to mention here the transformation and education of Higgins himself (has he learned from the experience?) along with the experience of the other characters, namely, Alfred Doolittle, Eliza's father.