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