There is no dedicated icon in draw.io to represent a "Lambda function with its layers". But you can do this to complete your architecture if it floats your boat :-
Stack small rectangles or boxes under or beside the Lambda icon.
Label them Layer 1, Layer 2, etc., or with more meaningful names (e.g., "Shared Utils", "Logging", "DB Client").
and then connect them to the Lambda icon with arrows (or brackets) to indicate that they are part of the Lambda execution environment.