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