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