The independent organisation runs schools and colleges for children and adults with a range of complex needs within the autistic spectrum.
The Hesley Group's facilities include residential schools as well as purpose-built villages that provide supported living.
The agency's appointment coincides with the publication of the results of an inquiry earlier this month by the All Party Parliamentary Group on Autism. The report concluded local councils were failing young people with autism by not providing adequate support to help with the transition from school to adult life.
Clew will raise awareness of Hesley's work through news stories, features and opinion pieces in the mainstream media. It will also create opportunities for the company to participate in public debates around 'inclusion', which centres on whether a child with special needs is catered for in mainstream schools.
The agency will promote a discussion on 'transitional care', during which a young person with special needs prepares to move into adulthood.
Phil Champion, principal of central services at The Hesley Group, said: 'We brought Clew on board to help us tell our story at an intellectual level, engaging with academics and thought leaders in the field.
'Most importantly, we want to show the human side of what we do - be it through the eyes of the student residents, the parents or the teachers, carers and healthcare professionals who make up the Hesley community.'