Hello @Adusumalli, Haripriya , I understand that you've federated AWS Cognito with Entra ID as a SAML IdP. This case is covered at Scenario: You have a SAML token and want to call the Graph API. Basically, you would leverage the Entra ID session cookie which is the same regardless of the protocol used (SAML or OIDC) to authenticate during the Microsoft Graph access token request.
To call Microsoft Graph from React applications take a look to React single-page application using MSAL React to sign-in users and call Microsoft Graph API (direct call) and Authenticate a user with Azure AD using msal.js and call an Azure AD protected Node.js Web Api using on-behalf of flow (delegated call).
Let us know if you need additional assistance. If the answer was helpful, please accept it and rate it so that others facing a similar issue can easily find a solution.