There are 6 of us travelling from Hong Kong airport to the intercontinental Kowloon

You must refer to InterContinental Grand Stanford, right?
You can take the bus A21 to Grabville Road, Chatham Road South. Then you can reach the hotel in 10 mins walking. The bus fare is HKD33, and the travel time is about 70 m ins.

Or you can take the airport express to Kowloon Station, and then take the free shuttle bus K3 to the hotel directly. You six can buy two group tickets. The fare is HKD190 for three people.