One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(6,10)(8,11)(15,16)(19,20) involution — undirected(1,2,4,3)(5,6)(7,11)(8,12)(9,10)(13,14,18,17)(15,20,16,19)(21,22,25,24)(23,27,28,26)(13,15,18,16)(14,19,17,20)(21,23,25,28)(22,26,24,27)(1,2,4,3)(5,7,9,12)(6,11,10,8)(13,16,18,15)(14,20,17,19)(1,3,4,2)(5,8,9,11)(6,12,10,7)(13,17,18,14)(15,20,16,19)(21,24,25,22)(23,27,28,26)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.