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