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