As it stands right now your student visa is expired and your entitled to work under that visa is no longer applicable.
Until you have been granted a settlement status under FLR you are not able to work unless UKBA/Home Office have written to provide a different status.
If you apply for and are offered another job neither you nor the employer will be able to provide the needed documentary evidence.
On the positive side, since you already applied for FLR before your student visa expiry then your immigration status is at least preserved.
Hope that helps.
