These are the charms that I have that I think work well for someone graduating. They are antique silver plated and the bangle or chain or keychains can be purchased separately as well.
WORDS/PHRASES
Follow your heart
Congrats heart
Dream
Dream a little dream
And so the adventure begins
She believed she could so she did
SYMBOLIC
Compass (to help you find direction)
Grad hat with tassel
key (the key to the next part of life)
little bird (symbolizing spread your wings and fly or soar)