Cayley Diagrams

Build stunning diagrams that reveal a group's entire structure at a glance

Cayley Diagrams

A Cayley diagram is a directed graph that encodes the entire structure of a group at a glance. Each node represents a group element and each colored arrow represents multiplication by a generator. Follow the arrows from the identity to discover every element.

Named after Arthur Cayley, these diagrams reveal symmetry, subgroup structure, and the "shape" of a group in a way that multiplication tables cannot.

Building a Cayley Diagram

Watch the diagram build itself node-by-node via BFS from the identity. Each step discovers a new element by multiplying an existing element by a generator. Colored arrows show which generator was used.

r
s

Step 1 / 18

Key insight: The BFS construction mirrors how generators create the entire group. The number of steps to reach an element from the identity is its "word length" in the generators.

Cayley Diagram Gallery

Browse pre-built Cayley diagrams for various groups. Click any node to highlight its outgoing edges and see the element's label and order.

r
s

Click a node to highlight its outgoing edges.
Order: 6

Key insight: Different groups have strikingly different diagram shapes. Cyclic groups form circles, dihedral groups look like polygons with spokes, and the quaternion group Q8 has a distinctive 3D-like structure.

Path Tracer

Type a word using the generators and watch it trace a path through the Cayley diagram. Each letter follows the corresponding colored arrow. Different words can lead to the same element -- these are the group's relations.

Type a word using generators r and s for S3, then trace the path through the Cayley diagram.

Key insight: A group is completely determined by its generators and relations. For S3: r^3 = e, s^2 = e, srs = r^-1. Try words like "rrr" or "ss" to see them loop back to the identity.

Key Takeaways

  • Cayley diagrams -- directed graphs encoding the full structure of a group
  • Colored arrows -- each color represents multiplication by a generator
  • BFS construction -- building from identity discovers all elements
  • Words and relations -- different generator sequences may reach the same element