Is this a DA/SA Sig or DAK?
Also. No Sig except for their specific 1911 versions is intended to be carried cocked and locked.
They are either DAK in which the trigger is never locked back because it has no single action.
Or they are DA/SA in which they are intended to be carried hammer down, round in the chamber. Pull the trigger on one heavy DA pull than the remainder of the shots would be SA.
There firearms do not have manual safeties (except for the .22 mosquito).
Picture would be helpful