Cache not updating on mutation in apollo server cache

I am using apollo-server-caching in apollo server, on mutation requests, cache is not getting updated and I am getting old cached data on refetch of a query after mutation in frontend

Can anyone guide me, how I can handle cache update on mutation in apollo server?

Below is my code implementation of server cache

export class MemoryCache implements KeyValueCache {
  cache: { [key: string]: string } = {};
  async get(key: string): Promise<string> {
    console.log(`get ${key}`);
    const value = this.cache[key];
    return value;
  }
  async set(key: string, value: string): Promise<void> {
    console.log(`set ${key}`);
    this.cache[key] = value;
  }
  async delete(key: string): Promise<void> {
    console.log(`delete: ${key}`);
    delete this.cache[key];
  }

  async reset() {
    this.cache = {};
  }
}