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