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