"Graag" is a difficult word to translate. It's an adverb and when used with verbs that mean "to want", it can mean two different things: that you are trying to be polite, or that you want it really badly. It is usually clear from the context which one of the two is meant. In the first case, a good translation would be the more polite "would like". In the latter case, "graag" is usually amplified to "heel graag" and then there is no suggestion of politeness. For example, "Zij willen heel graag een olifant" would mean "They really want an elephant".
As a side note: when used with other verbs, "graag" typically means "willingly, gladly". This is most commonly seen in the expression "graag gedaan!" (notoriously difficult to pronounce if you have trouble with the Dutch g sound), meaning "you're welcome!". The literal translation is "gladly done!".