The team comprised state ministers Firhad Hakim and Subhendu Adhikari and Trinamool Congress lawmaker Saugata Roy, Sudip Banerjee and Kakali Ghosh Dastidar.
They handed over Rs 2 lakh on behalf of the party to Mr Afrazul's wife Gulbahar and his daughters, and assured them all help.
The leaders also addressed a gathering and condemned the gruesome killing, describing the act as "inhuman".
Chief Minister Mamata Banerjee has already announced that the state government would provide Rs 3 lakh and a job to the family, Adhikari said.
A condolence meeting was also held in memory of the deceased labourer.
Raigar was yesterday sent to three days in police custody and his nephew to a juvenile home by a court in Rajsamand even as Ms Banerjee demanded "exemplary action" against him, calling the incident "very sad".
She had also asked the state's director general of police to speak to his Rajasthan counterpart and ensure security to nearly 3,500 labourers from West Bengal working in that state.
State Congress president Adhir Chowdhury and the party's Rajya Sabha member Pradip Bhattacherjee also met Afrazul's family and assured them all assistance.