One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6,9,8)(7,11,12,10)(13,14,18,19)(15,20,17,16)(21,22,24,26)(23,25,27,28)(14,19)(15,17)(23,27)(25,28) involution — undirected(1,2,3,4)(13,15,18,17)(14,20,19,16)(21,23,24,27)(22,25,26,28)(5,7,9,12)(6,10,8,11)(13,16,18,20)(14,15,19,17)(5,8,9,6)(7,11,12,10)(13,17,18,15)(14,20,19,16)(21,22)(23,25)(24,26)(27,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.