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