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