Well, you take a dragon... and you add the Lich template.
The closest thing in Pathfinder is the ravener template for dragons. I'm pretty certain there is no official "dracolich" like there was in 3.5.
Oh, right, Ravener is also something to fill the same niche. Both can work, as dragons naturally come with a Sorcerer caster level (e.g. an Old category Red Dragon qualifies for the minimum caster level 11th needed to create the phylactery). I would imagine a Ravener would be far less subtle, so I'd probably use Lich for the manipulative mastermind type of baddie.
yeah, the ravener looks like a tarrasque type of monster, the kind that lays waste everywhere it goes (and it's often on the move)... a lich is more a mastermind, staying quietly in its lair.