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