Be honest with the interviewer. Leadership may not be everyone's strength, but you can still describe an instance in which you showed initiative.

"I wouldn't say I'm a natural leader, but I do enjoy situations when I'm able to creatively execute my ideas. Once, when a group of Japanese students visited our school, I had the idea to serve sliders and fries in the form of a Japanese tea ceremony and I worked with a few colleagues to arrange the setup and room decoration. The visiting students really enjoyed it."