There is a tendency to pigeonhole all "unusual" behaviours together into one group. However, when examined more closely, one sees very distinct conditions.
Transgenderism, gender dysphoria and transsexualism are quite distinct from sexual preference and homosexuality. A person's sexual preference is the physical nature of their preferred sexual partner, that is, the anatomical sex of the person they desire sexually. This preference is independent of a person's own gender identity. Moreover, homosexuals desire people with the same anatomical sex as themselves. They do not necessarily have gender dysphoria, and can be content to remain as males or females.
Transvestites and cross dressers are males who like to appear as women at times. In this respect they are transgendered. However, they are quite distinct from transsexuals in that they do not necessarily wish to alter their body, and they can be content to live as males for the vast majority of the time. Drag queens are exhibitionist homosexual males who like dressing in an extreme feminine manner for some of the time. Their over-the-top appearance intentionally distinguishes them from women. In contrast, a transwoman dresses to be a woman and pass unnoticed as such. The same is true for a transman, (i.e. dressing as a man and passing unnoticed as such).