Your dracaena will take some time to recover from the transition to a new pot. It will have lost some of its fine roots and will need to adjust to new soil. Be patient for that to happen and just give it the best possible care for the time being. As long as the roots looked healthy to you when you transplanted (not soft, slimy, mushy or smelly), it should stabilize with time and sensitive care. 

Here is the care routine it needs to help it along:

• give bright light daily, but do not place in direct sunlight. The best light condition gets two or three hours a day of sunlight filtered through a translucent blind or curtain.
• keep it away from air conditioning and heat vents which dry out the leaves and soil too quickly
• during active growth, water plentifully and keep potting mixture constantly moist. It is essential that you toss excess water left in saucer after 15 minutes. Reduce water in winter but do not allow the root ball to dry out. Too much water in the winter is a frequent cause of plant death.
• abundant humidity is required for healthy growth. Moist air can be supplied by placing plants on water filled pebble trays. Place plant with saucer on pebbles to avoid wet feet and eventual rot. Mist regularly. If you notice that your plant's leaf tips are brown, your space may be too dry.
• provide a temperature range of 65 – 75º F. Cold drafts from being placed too close to windows or air conditioning units can lead to brown leaf tips and curling brown leaf margins.
• apply standard liquid plant fertilizer every two weeks while the plant is in active growth.

Courtesy of NYBG Plant Information Service