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