In your GoDaddy account select Set Nameservers and then I have specific name serversfor my domains(Documented here)

Enter webfaction's domain name servers (Documented here):

ns1.webfaction.com  
ns2.webfaction.com  
ns3.webfaction.com  
ns4.webfaction.com  

The docs say to wait atleast 2 hours but I found my website worked immediately.